Randy, In cases like your, an antenna analyzer comes in very handy. Do the normal "thing" to make your remote tuner tune the antenna - then remove the coax from the K3 and attach it to the antenna analyzer. What is the SWR? If it is sufficiently close to SWR=1, then you have a K3 problem, if it is not near 1, then you have an antenna/feedline/tuner problem, and you can further break it down by measuring at different points in the antenna system.
Don't have an antenna analyzer? Ask if one of your local hams have one they would be willing to lend, or they might even offer to take it to your house and help you locate the problem. 73, Don W3FPR On 11/9/2011 1:28 PM, Randy Cook wrote: > I have a weird problem that I could use help on. I have limited experience > with antennas, so the answer could be something simple I have overlooked. > > I am using a K3/100 with the ATU. I recently installed a 31 foot vertical > antenna with ground radials and a balun at the base. The MFJ analyzer shows > an SWR (at my K3) below 1. 3:1 on 40M and near 15M as you would expect. SWR > for the other bands are much higher, about 4:1 for 17, 12, and 10. But, the > K3 tuner trims up fine. I understand the efficiency is hit, but it does work. > On 20M, the SWR is near 6:1. Again, I can tune it with the K3, but I am not > getting out well. These results are the same with the Electraft BL2 balun OR > a DX Engineering line choke installed. There is about 80 feet of LMR-400 > between the rig and the antenna. I also have a static/lightning arrestor in > line. > > In doing some research, it seems that a remote tuner at the antenna base > would be a more efficient system. I purchased a remote tuner kit from DX > Engineering, that includes an MFJ 927 tuner at the base (along with a mount > and a line choke). I bypassed the internal K3 tuner. With the remote tuner > in place, the SWR HI message is displayed on my K3 when I try to transmit > most of the time, and on all bands. The tuner was checked out by MFJ under > warranty, and came back fine. I reinstalled it, and have the same problem. > > I verified that 12 volts is getting to the tuner. Bypassing the lightning > arrestor makes no difference. Going back to the K3 and no remote tuner works > as before. > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
